Printing process



Patented A r-.25, 1944 UNITED STATES v PRINTING PROCESS George W. Seymour, Cumberland, Md., assignor to Oelan tion of Delaware ese Corporation of America, a corporat No Drawing. Application October 14, 1940,

Serial No. 361,103

6 Claims.

This invention relates to a process of dyei'ng fabrics, and relates more particularly to theapplication printing of fabrics by the use of printing paste compositions.

An object of my. invention is the formulation of printingpaste compositions which fully pen'etrate the fabrics upon which they are applied.

Another object of my invention is to obtain printed fabrics in which the designs are level in shade and free of mottling. A further object of my invention is the formulation of printing paste compositions which are especially suitable for use with fabrics containing organic derivatives of cellulose.

Other objects of my invention will appear hereinafter from the following detailed description.

Printed textile fabrics in which the designs are composed of various colors have long been known to the art. These designs may be obtained in numerous, ways. Generally, they are obtained by applying a printing paste composition to the fabrics whereby, depending upon the formulation of the printing paste composition, a variety of color eifects may be obtained. Thus, fabric dyed in any suitable ground color may be printed in a particular pattern with a paste containing a dis- A charging agent for the ground color. After the j discharging action has been caused to take place by appropriate treatment of the printed fabric, a

white pattern, where'the paste has been applied, on a colored ground is obtained. If the paste contains a dyestufl together with the discharging agent an illuminated discharge is obtained, that is, one in which the discharged portion of the colored ground is colored by thedyestuifin the paste composition after the ground color h: s been destroyed by the discharge agent. Likewis i, white fabrics may be printed in patterns of many colors by treating them with printing pastes containing various dyestuil's and applying these pastes in any desired pattern.

The discharge agents and the dyestuffs are generally applied to the fabrics in the form of a thick paste so that the area they cover may be controlled and the pattern in which they are printed may 'be accurately reproduced on the fabric. Various'thickening'and adhesive agents may be used in the formulation of the printing pastes and among the many agents which may be used are gum traga'canth, gum arabic, agaragar, gumsenegal, albumin, starch and British gums or dextrins. The British gums or dextrins are derived from starch. One method of preparing these gums is to thoroughly cook and bydrolyze it in enclosed chambers. Still another method comprises subjecting'the starch to en- .zymatic action. The resulting products are known asBritish gums or dextrins and may diil'er somewhat in composition depending upon the 60 5 thick, gummy masses which have excellent adhesive properties and may be compounded or formulated into printing pastes by incorporating therein the desired dyestuffs, discharge agents and other desired inert or chemically active agents. While these pastes are suitable for the printing of light and loosely-woven fabrics, the results on heavier and more closely woven fabrics have not always been as even, as uniform or as deep in the fabric as desired.

I have now discovered that if the printing pastes are formulated using a gum base of incompletely hydrolyzed starchesas theprint paste thickener and adhesive, excellent and unusual penetration of the dyestuff into the fabric is, obtained and the resulting prints are free of uneven, mottled or spotted areas.

' Thus, the starch gums suitable for'ilSe in accordance with my invention may be prepared by incompletely hydrolyzing starch by heating the starch in water in the presence of a hydrolyzing catalyst such as hydrochloric, nitric or sulfuric acid. In order that the starch be incompletely ydrolyzed the conditions under which it is heated must be carefully-controlled. The starch may be heated in water to temperatures of about F. to 205 F. for periods of time ranging from 10 minutes to 4 hours. Where a catalyst such as nitric. sulfuric or hydrochloric acid is used to aid the hydrolysis, the mixture may be heated at reduced temperatures for shorter times. The amount of acid used will vary but in general from about 0.01% to 0.10% of concentrated acid based on the weight of the starch is sumcient to catalyze the hydrolysis so that when the starch is heated under the conditions described, the reaction will not be complete. starches such as, for example,

corn, rice, sago, potato, wheat, tapioca or cassava starch may be treated in accordance with my invention and excellent starch gums may be obtained.

In addition to the starch gum base and the dyestuffs, used in the formulation of the printing paste composition, other agents such as textile gum or other type of vegetable gum or British gum may be incorporated therein to give the resulting paste other desirable properties. In addition it is-sometimes desirable to include organic water-soluble dyeing assistants which are for the most part solvents for the dyestuif. Assistants such as glycerol, glycols, etc., glycerol formals, and other formals and Glyezine A" (i. e. thiodiglycol) may be used.

The pastes may be applied to the fabric in the may be printed on by means of engraved or emderivatives of cellulose.

without being limited thereto the bossed rolls, they may be brushed on, or else they may be sprayed on through stencils or screens.

While these printing pastes may be used for the printing of fabrics of cotton, silk, wool and the regenerated cellulose type of artificial fiber, they are especially suitable for the printing of fabrics made in whole or in part of organic Examples of organic derivatives of cellulose are cellulose esters such as cellulose acetate, cellulose propionate, cellu lose butyrate and mixed esters such as cellulose acetate-propionate and cellulose acetate-butyrate, and organic ethers such as ethyl cellulose, methyl cellulose and benzyl cellulose. A mixed material may be one of cellulose acetate and cotton.

In order further to illustrate my invention but following example is given:

' Example 300 parts of wheat starch are mixed with 1700 parts or water, heated to a temperature about 175 F. and maintained at'approximately that boiled and is partially but incompletely hytration and that many variations may bemade therein without departing from the spirit of my invention. 1 Having described, my invention, what I deslr to secure by Letters Patent is:

1. In the process of producing local fects upon textile materials, the step of locally applying thereto a paste comprising a substance 2. In the process 01' producing local color effects upon textile materials containing cellulose acetate yarns, the step of locally applying there a paste comprising a substance capable oi efle'cting color chan e and, as thickening component,

' temperature for about 2 hours. The starch is un.

drolyzed by this treatment and is left in"a thick is thoroughly mixed to a smooth homogeneous mass and applied to a cellulose acetate iabric of heavy sharkskin weave by means of engraved .rolls. The printed fabric isdried and then passed through a suitable ager where it is'sub- 'jected to the action of wetsteam under 5 lbs.

pressure for about 15 minutes. The fabric is 'then lightly soaped and -finished as required,

yielding a red print on a white background.

Altemativelv, a. somewhat thicker printing paste may be used consisting oi:

, I Parts Celliton Fast Pink F'F3B (Schultz, Second Supplement, -page 142), 25% groimd in commercial British gum 100 Wheat starch paste 100 'Water L 200 n is to be understood that the foregoing .de-

tailed description is given merely by way orilluscapable of eflecting color change and, as thickening component, starch that has-been heated in water alone at a temperature of 150 to 205 F. for from 4 hours to 10 minutes.

- 4. In the process oi! producing local 'colofeffects upo textile materials containing cellulose acetate yarns, the step of locally applying thereto a paste comprising a substance capable oi. eifecting color chang and, as thickening component, starchthat has been heated in water alone at a temperature of 150 to 205 F. to from 4ho'urs to 10 minutes.

5. A printing composition for application to textile materials comprising a substance capable of effecting color change and, as thickening component, starch that has been heated in water containing at most 0.10% of mineral acid based on the weight of the starch at a temperature of to 205 F. m;- from 4 hours to 10 minutes. 7 6. A printing composition for application to textile material comprising a substance capable m of 'efiecting color change and, as thickening component, starch that has been heated in water alone at a temperature of 150 .to 205 F. for from" color ei- 

